Preparation Of Polyacrylate Emulsion Used In Waterborne Gravure Ink And Printability Study Of The Ink

As a new type of green environmental printing materials, water-based gravure ink has become an important development direction of printing ink. Currently, water-based gravure inks are widely used in paper printing. However, due to the reason for its poor adhesion to the plastic substrate, it cannot replace solvent-based inks. This has become one of the important factors that hinder the development of water-based gravure ink. In order to obtained the water-based gravure printing ink which can apply to plastic films with great printability and adhesion property, this topic had modified the polyacrylate emulsion which used in waterborne gravure ink.In the study of polyacrylate emulsions, the core-shell structure polyacrylate emulsions were successfully synthesized by emulsifier-free seeded emulsion polymerization with MMA/BA as main monomers, G01 as a functional monomer. In accordance with monomer conversion rate, gel rate, stability, etc, the influence of emulsifier, initiator and temperature on polyacrylate emulsions and films were investigated. In accordance with adhesion fastness, the influence of G01 and cross-linking monomers on polyacrylate emulsions and films were investigated. The results showed that:The system stability of polyacrylate emulsion and adhesion fastness of the polyacrylate film were excellent when the emulsifier was 3%, initiator was 0.6%, functional monomer was 15% and crosslinking monomer GMA was 3% and temperature was 80℃. The chemical components of polyacrylate films were investigated by FTIR, The results showed that New peaks at about 691 and 619 cm-1 which were attributed to the stretching vibration and wagging vibration of C-F bond but no absorption peak of C=C at 1650cm-1 indicating main monomers, functional monomer, etc, were fully participated in the emulsion copolymerization. The emulsion particle size was about 90nm with a narrow distribution and the particles had obvious core-shell structure through TEM analysis.In the study of water-based gravure ink printability, in accordance with adhesion fastness, viscosity, early dry and tinting strength, the factors affecting the properties of the water-based gravure ink printability were investigated by orthogonal test. The results showed that: Modified acrylate emulsion, water-soluble acrylic resin had significant effect on adhesion fastness, cosolvent and water-soluble acrylic resin had significant effect on viscosity and initial drying, pigment had significant effect on tinting strength. The optimum combination of the ink components was A4B2C2D2. The optimized water-based gravure printing ink formulation was as follows:emulsion 56～60%, cosolvent 9-13%, water-soluble acrylic resin 22～25%, pigment 9-12%, additives 3～4%. The color, fineness, viscosity, tinting strength and adhesion fastness of water-based gravure ink had met the standard of GB/T 26394-2011.